Grinding wheel



Nov. 7, 1939. c. J. HUDSON 2.178.835

GRINDING WHEEL Filed June 19, 1957 INVENTOR J CHARL ES 1.]. HUDSON "IL1 J 7 ATTORNEY Patented Nov. 7, 1939 UNITED STATES PATENT OFFICE aliases GRINDING WHEEL Charles J. Hudson, West Boylston, Mass., assignorto Norton Company, Worcester, Mass, a corporation of Massachusetts Application June 19, 1937, Serial No. 149,121

ZClaims.

The invention relates to grinding wheels, par

ticularly to wheels made from a plurality of secors. One object of the invention is to provide a thoroughly safe means and method of reinforcing a wheel of the type indicated. Another object of the invention is to provide an extremely strong composite wheel structure for face grinding. Another object of the invention is to providea simple and efilcacious method for making the wheels .of the type indicated. Other objects will be in part obvious or in part pointedout hereinafter. Y

The invention accordingly consists in the feall-tures of construction, combinations of elements, and arrangements of parts, and in the several steps and relation and order of each of said steps to one or more of the others thereof, all as will be illustratively described herein, and the scope go of the application of which will be indicated in the following claims.

In the accompanying drawing which illustrates one of many possible embodiments of the mechanical features of this invention,

Figure 1 is a. front elevation of a grinding wheel constructed according to this invention,

Figure 2 is a radial sectional view, taken on the line 22 of Figure 1,

Figure 3 is a plan'view showing the method of so constructing the wheel,

Figure 4 is a sectional view, taken on the line 4-4 of Figure 3,

Figure 5 is a view on a reduced scale illustrating a quantity of the material for the reinforcing band.

Referring first to Figure 4, I provide a plurality of sectors III 'of abrasive material, for example of silicon carbide or aluminum oxide bonded with any desired bond, for example vitrified clay bond,

silicate bond, resinoid or natural resin or rubber bond. I place these sectors ill on a steel plate H to form a circular disk of abrasive, as shown in Figure 3. One by one to each radial edge of each sector I apply, as by means of a trowel or the like, a spread of litharge. After each individual sector l0 has its two radial edges coated with litharge, I place it in the appropriate position to make the composite wheel, as shown in Figure 3.

I provide a reinforcing circumferential band l2 which I place outside of the assembly of sectors. as shown in Figures 3 and 4. This band I! may 7 be cut from a large tube It, as shown in Figure 5. I prefer that the band l2 shall be of relatively is soft material and yet of high tensile strength. I

have found that if heavy paper impregnated with liquid synthetic resin, for example liquid phenol formaldehyde,-is wound upon a drum under tension and then cured with a heat and for a length of" time ordinarily used to cure phenol-formalde I hyde resins, there is produced a tube l3 from which may be cut bands l2 having great tensile strength, and sufllcient elasticity and resiliency for making the wheel according to the present invention, and yet'which will wear away during a. 10 grinding operation or pursuant to truing or dressing of the grinding wheel so that there is never any detrimental amount of the band I2 proiecting over the side face of the wheel.

The band I2 is of such diameter as compared 15 with that of the sectors i0 that it will just fit over them when they have been assembled in the relationship shown in Figure 3. On the other hand, the individual sectors Ill may be placed inside of the band. I now place a plurality of 2 small wooden sectors IS in the central hole of the wheel being manufactured. Each wooden sector l5 has an interiorconical surface on the inside face. I place a wooden cone It in contact with the inner faces of all the sectors It. 85 The wooden cone it has a central axial bore I! through which extends a bolt I8. I provide a cup is having a central hole for the bolt [8. I provide a washer 20 adjacent the head 2| ofthe bolt l8 to prevent the bolt from passing 30 through the hole in the cup IS. The plate I I has a hole to receive the small end of the cone I 6 and also the bolt Hi, all as shown in Figure 4. I now place a washer 22 around the other end of the bolt I8 and place a mit 23 on the threaded 85 end of the bolt, I now tighten the nut 23, which forces the cone l6 downwardly, thus spreading the wooden sector blocks l5, and thereby forcing outwardly the several abrasive sectors Hi. All this is done before the litharge has a chance to (0 set. The litharge is then allowed to set and thereafter the bolt l8, cone I6 and wooden sector blocks 15 are removed. The wheel is now complete and is ready for mounting. It will be noted that the band I2 is under tension so that centrifugal force tending to drive the sectors it apart is to a large extent overcome by the centripetal action of the annular band l2.

Either during the manufacture of the sectors it or thereaftena plurality of depressions 25 are formed in one face thereof. At any stage in the manufacturing operation, conical nuts 26 are imbedded in the depressions 25 by means of Babbitt metal 21. The' complete wheel 30 is shown in Figure l and consists of a plurality, for example 86 six, sectors [I cemented together with litharge ioints- 3i and surrounded by a paperresinoid ring I: under tension. This wheel 33 may be mounted upon a face plate 32 by means of bolts 33 which extend through the face plate 32 and into nuts 23. The face plate 32 is mounted upon a spindle 34 in any suitable manner, as by means of screws 35.

In the use of the wheel II, the exposed. face is used to grind. As the wheel wears, it becomes thinner, and may be trued from time to time with any suitable dressing instrumentality which will readily cut the resinoid paper ring or band II. A particular feature of the ring or band I I is that under no circumstances can it injure any one. Composite wheels made with wire windings have beenusedandthewirewindinghasbeenapotential source of danger in case; of breakage.

. With thering I2 under considerable tension due to the manner of manufacturing the wheel described, the centrifugal force tending to cause the sectors iii to fly outwardly is to some extent sul, which is substantially sulphur with a small percentage of carbon, and many other types. Also, other substances besides babbit may be used to imbed the nuts 23, for example lavasul or plain sulphur. Also, babbit might be used between the sectors. Instead of using a ring or band I 2 made of paper impregnated with resinoid, aband made of resinoid impregnated cloth might be used. Instead of resinoid, i. e. synthetic resin, rubber might be substituted.

It will thus be seen that there has been provided by this invention a method and an.article in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. Asvarious possible embodiments might be made of the mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. Article of the class described comprising a plurality of bonded abrasive uni-diameter sectors, cement securing said sectors together in the form of a wheel, and a peripheral band outside of said sectors and in a state of tension exerting a compressive force against them and comprising paper impregnated with resinoid, the article constituting a grinding disk, the plane face of which ,does the grinding and the peripheral band wearing away as the disk is used.

2. Article of the class described comprising a plurality of bonded abrasive uni-diameter sectors, cement securing said sectors together in the form of a wheel, and a peripheral band outside of said sectors and in a state of tension exerting a compressive force against them and comprising impregnated sheet material wound in a plurality of layers ani cured, the article constituting a grinding disk, the plane face of which does the grinding and the peripheral band wearing away as 'the disk is used. 1

CHARLES J. IQIUDSON. 

